Semiconductor device structure and methods of forming the same

Abstract

A semiconductor device structure and methods of forming the same are described. The method includes forming a fin structure from a substrate, depositing a first semiconductor material on a first semiconductor layer of the fin structure, depositing a second semiconductor material on the first semiconductor material, depositing an interlayer dielectric layer over the second semiconductor material, forming an opening in the interlayer dielectric layer to expose the second semiconductor material, performing a first implantation process to form an amorphous region in the second semiconductor material and to implant a first species in the amorphous region, and performing a second implantation process to implant a second species in the amorphous region. The second species includes fluorine, nitrogen, or carbon. The method further includes performing an annealing process to recrystallize the amorphous region.

1 . A method, comprising:
 forming a fin structure from a substrate;   depositing a first semiconductor material on a first semiconductor layer of the fin structure;   depositing a second semiconductor material on the first semiconductor material;   depositing an interlayer dielectric layer over the second semiconductor material;   forming an opening in the interlayer dielectric layer to expose the second semiconductor material;   performing a first implantation process to form an amorphous region in the second semiconductor material and to implant a first species in the amorphous region;   performing a second implantation process to implant a second species in the amorphous region, wherein the second species comprises fluorine, nitrogen, or carbon; and   performing an annealing process to recrystallize the amorphous region.   
     
     
         2 . The method of  claim 1 , wherein the second semiconductor material comprises SiP and the first species comprises phosphorous. 
     
     
         3 . The method of  claim 1 , wherein a concentration of the first species in the amorphous region ranges from about 1×10 19  cm −3  to about 5×10 20  cm −3 . 
     
     
         4 . The method of  claim 3 , wherein a concentration of the second species in the amorphous region ranges from about 5×10 20  cm −3  to about 1×10 21  cm −3 . 
     
     
         5 . The method of  claim 1 , wherein the fin structure comprises the first semiconductor layer, a second semiconductor layer located below the first semiconductor layer, and a third semiconductor layer located below the second semiconductor layer. 
     
     
         6 . The method of  claim 5 , further comprising depositing the first semiconductor material on the second and third semiconductor layers. 
     
     
         7 . The method of  claim 6 , wherein a bottom of the amorphous region is located at a level between the first semiconductor layer and the second semiconductor layer. 
     
     
         8 . A method, comprising:
 forming a fin structure from a substrate;   depositing a first semiconductor material over the substrate;   depositing an interlayer dielectric layer over the first semiconductor material;   forming an opening in the interlayer dielectric layer to expose the first semiconductor material;   performing a first implantation process to form a first amorphous region in the first semiconductor material and to implant a first species in the first amorphous region;   performing a second implantation process to form a second amorphous region in the first semiconductor material and to implant a second species in the first and second amorphous regions; and   performing an annealing process to recrystallize the first and second amorphous regions.   
     
     
         9 . The method of  claim 8 , wherein the first species comprises phosphorous and the second species comprises fluorine, nitrogen, or carbon. 
     
     
         10 . The method of  claim 8 , wherein the fin structure comprises a plurality of semiconductor layers. 
     
     
         11 . The method of  claim 10 , further comprising depositing a second semiconductor material on each semiconductor layer of the plurality of semiconductor layers, wherein the first semiconductor material is deposited on the second semiconductor material. 
     
     
         12 . The method of  claim 11 , wherein the second amorphous region is wider and deeper than the first amorphous region. 
     
     
         13 . The method of  claim 12 , wherein the first amorphous region is located between portions of the second semiconductor material. 
     
     
         14 . The method of  claim 13 , wherein the portions of the second semiconductor material are part of the second amorphous region. 
     
     
         15 . A semiconductor device structure, comprising:
 a plurality of semiconductor layers disposed over a substrate; and   a source/drain region disposed adjacent the plurality of semiconductor layers, wherein the source/drain region comprises:
 a first semiconductor material in contact with each semiconductor layer of the plurality of semiconductor layers, wherein a first portion of the first semiconductor material in contact with a topmost semiconductor layer of the plurality of semiconductor layers includes a first species, and a second portion of the first semiconductor material in contact with a semiconductor layer of the plurality of semiconductor layers disposed below the topmost semiconductor layer has a gradient concentration the first species; and 
 a second semiconductor material adjacent the first semiconductor material. 
   
     
     
         16 . The semiconductor device structure of  claim 15 , wherein the first species comprises fluorine, nitrogen, or carbon. 
     
     
         17 . The semiconductor device structure of  claim 16 , wherein the second semiconductor material includes a second species. 
     
     
         18 . The semiconductor device structure of  claim 17 , wherein a second species comprises phosphorous. 
     
     
         19 . The semiconductor device structure of  claim 15 , wherein the second species has a concentration gradient that decreases in a direction towards the substrate. 
     
     
         20 . The semiconductor device structure of  claim 15 , further comprising a third semiconductor material disposed over the substrate and a dielectric layer disposed on the third semiconductor material, wherein the second semiconductor material is disposed on the dielectric layer.